renamed 16 bit version of transfer() to transfer16() as per the Arduino API

Author: rogerclarkmelbourne

STM32F1/libraries/SPI/src/SPI.cpp

@@ -360,7 +360,7 @@ void SPIClass::write(const uint8 *data, uint32 length) {
 	}
 }
 
-uint16_t SPIClass::transfer(uint16_t wr_data) const {
+uint16_t SPIClass::transfer16(uint16_t wr_data) const {
 	spi_tx_reg(_currentSetting->spi_d, wr_data); // "2. Write the first data item to be transmitted into the SPI_DR register (this clears the TXE flag)."
 	while (spi_is_rx_nonempty(_currentSetting->spi_d) == 0); // "4. Wait until RXNE=1 ..."
 	uint16_t rd_data = spi_rx_reg(_currentSetting->spi_d); // "... and read the last received data."

STM32F1/libraries/SPI/src/SPI.h

@@ -260,7 +260,7 @@ class SPIClass {
      * @return Next unread byte.
      */
     uint8 transfer(uint8 data) const;
-    uint16_t transfer(uint16_t data) const;
+    uint16_t transfer16(uint16_t data) const;
 
 	/**
      * @brief Sets up a DMA Transfer for "length" bytes.